Cutter head sharpening attachment



Nov. 11, 1952 SACREY 2,617,237

CUTTER HEAD SHARPENING ATTACHMENT Filed March 11, 1950 2 SHEETS-SHEET 1 IN V EN TOR.

iii/viz B Jazzy JZY'OZ/PZYU E. P. SACRE Y CUTTER HEAD SHARPENING ATTACHMENT Nov M, 1952 2 SHEETS-SHEET 2 Filed March 11, 1950 INVENTOR. 22/2221? Jim BY JZ'Z'O/LZFZYJ' Patented Nov. 11, 1952 UNITED STATES PATENT OFFICE 2,617,237 CUTTER STIA RPENING ATTACHMENT I Elmer P. Sacrey, Syracuse, N.-Y. Application March 11, 1950, Serial No. 149,192 2 Claims. (01. 51-123) This invention relates to spiral bIadecutter heads and a sharpening fixturefor the cutters. The cutters are of the type used in planes having motors for rotating the cutters as, for example, the type of plane and the" general typef of spiral cutters shown in Patent No. 2,221,458,. issued November 12, 1940.

The invention has for its objecta particularly simple and eflicient fixture for quickly sharpening the spiral blades of the cutter heads.

More specifically, th invention has for its object a fixture comprising generally a base having means to which an electric motor can be detachably or interchangeably mounted, which motor actuates a grinding wheel and a support on the base, as a shaft, for the cutter head during the grinding thereof, a fixed guide means for giving a rocking movement to the cutter toguide the blade against the grinding wheel duringreciprocation of the shaft and the cutter head, the guide being of the same" spiralcontour as the blade.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure l is a plan view of the fixture embodying v this invention, the motor being indicated in broken lines.

Figure 2 is an end view looking upwardly in Figure 1.

Figure 3 is a fragmentary sectional view of the base on line 33, Figure 1.

Figure 4 is an enlarged sectional view on line 4l, Figure 1.

Figure 5 is a sectional view on line 5 5, Figure 4.

Figure 6 is a sectional view on line 6 6, .Figure 1.

Figure 7 is a sectional view on line f|--- Figure 2.

Figures 8 and 9 are respectively an end view and a side elevation of the cutter head.

I designates the base, this having suitable pronged feet 2 by which it is held from sliding on a supporting surface. The base has a annular support 3 to which an electric motor 4 can be detachably secured in horizontal position, the shaft of the motor supporting a spindle 5 for a grinding wheel 6. The motor 4 is usually the motor used in the plane or other motor operated wood working tool and is readily detachable from 2 the plane, or other tool, and attachable to the annular motor support 3 to interlock lugs 1; Figure 2, on the annular support with lugs 1A on the motor, by successive axial and partial turning movements. See, for instance, Patent No. 1,899,883, February 26, 1933.,

8 designates a carriage movable alongguide rods 53 and it on the base, these rods being parallel to the axis of the motor or the spindle 5 of the grinding wheel 6. l I designatesthe support or shaft on which the cutter head I2 is mountable, this extending transversely of the grinding wheel 6 beyond the end of the same, as seen in Figures 1 and 2, and also being shiftable endwise and having a rocking movement. The shaft is supported on the base by the carriage 8. The cutter head 12 is provided with spiral cutting blades l3. Each of these blades extends from end to end of the cutter and is less than one-half of a convolution. The bladesare so spaced that only one of the blades is in cutting position at any time during the rotation of the cutter head in use in the plane. As here shown, there are two diametrically opposite blades IS. The cutter head I2. is demountable from. the plane and mountable on the shaft l I, and the shaft is moved endwise with one blade against the grinding wheel, the shaft being given a rocking movement during the endwise reciprocating movement. The rocking movement is effectedby a spiral cam guide of the same contour as the spiral blade. The guide is fixedto the carriage 8 and is in the form of a sleeve I 4 surrounding the shaftand having thev same number of spiral cams I5. as there are, bladeson the cutter head and theshaft is provided with a follower, or followers 16,,for following alongone or both of the spiral, cams during the reciprocating motion of the shaft and thus rocking the shaft H and guiding one blade against the grinding wheel. The cams are grooves, in the sleeve. Thesleeve or collar bearing i l is mounted in a collar l iA on the carriage 8 abovethe guide rod 9. When one blade is sharpened, the shaft is moved endwise far enough to move the follower, or followers, out of one groove, 0r grooves, and the shaft turned to aline with anther groovein this case a one-half turn to shift the other blade to engage the grinding wheel when the shaft is moved endwise to shift the follower, or followers, in the groove, or grooves.

In order to mount the cutter head on the shaft II and to demount it therefrom, one end of the shaft ll extends through a collar l8 located in an enlarged bearing I9 formed in a bracket 20 on the carriage 8, the bearing I9 being here shown as above the guide rod I0, the collar I8 being held from endwise movement and from rotation in the bearing by a spring catch 2|. The spring catch is shown as U-shaped embracing the hearing I9, with the arms embracing the collar I8 and seated in diametrically opposite transverse slots or notches 22 in the collar. The arms work in slots 23 in the bearing, which slots break through the bearing faces of the bearings in line with the notches 22 in the collar. Turning of the collar in the bearings separates the arms of the U formation, permitting the collar to be removed. The opening of the bearing is large enough to let the cutter head pass therethrough when on the shaft. When the cutter head is located on the shaft, the collar is replaced by reverse operating movements of the collar and the catch 2 I The cutter head is located on the shaft between the ends of a transverse shoulder or pin 25 on the shaft, and a nut 26 threading on the shaft. The nut 26 is formed with an annular chamfered end face pressing against the end of the bore of the cutter head for centering the cutter head on the shaft H. The ends of the pin 25 interlock in notches 25A in the opposing end of the cutter head for proper location of the cutter.

The carriage 8 is shifted forwardly and rearwardly to locate the cutter blades in proper con tact with the grinding wheel by an adjusting screw 21 mounted for rotation and held against endwise movement in the carriage 8 and threading axially into the guide rod 9. The adjusting movement by the screw 27 is against a spring 28 coiled about the guide rod 9 and thrusting against the carriage 8 at one end.

In operation, the motor 4 is removed from the plane and attached to the base I and the spindle, which usually carries the cutter head, is removed from the shaft of the motor and the sleeve 5, carrying the grinding wheel, is secured to the motor shaft. The removed cutter head is then applied to the shaft I I and the carriage adjusted to bring one cutter blade in proper position to the grinding wheel. With the motor running, the shaft II is moved back and forth endwise and, being guided by the spiral guide, holds one cutter blade up against the grinding wheel. When the grinding of that blade is finished, the shaft II is moved far enough endwise to carry the cutter head out of range of the grinding wheel and to detach the follower from the spiral groove of the cam guide, the shaft given a half turn so as to aline the follower with another groove and then axially to move the follower into the groove. The shaft is then given a partial turn to bring the other cutter blade up against the grinding wheel, and the reciprocating operation repeated.

What I claim is:

1. A sharpening fixture for a blade cutter head having a spiral blade of less than one convolution comprising a base, a carriage mounted for reciprocation on the base, the carriage having axially spaced collars, bearings in the collars, a reciprocating rock shaft mounted in and guided by said bearings, means for detachably securing the cutter head on the shaft to reciprocate and rock with the shaft, one bearing being formed with an internal spiral cam of less than one convolution and the same contour as the spiral blade of the cutter head, and the shaft having a follower movable along the cam during the reciprocation of the shaft, the other bearing being of greater external diameter than the cutter head, and means for demountably securing said other bearing in the companion collar; the base being also formed with means for supporting an electric motor having a rotary armature shaft and a rotating grinding wheel at its end to coact with a spiral blade of the cutter head during reciprocation and rocking of the shaft mounted in the bearings.

2. A sharpening fixture for a blade cutter head having a spiral blade of less than one convolution, said fixture comprising a base, a carriage mounted for reciprocation on the base, the carriage having axially spaced collars, bearings in the collars, a reciprocating rock shaft mounted in and guided by said bearings, means for detachably securing the cutter head on the shaft to reciprocate and rock with the shaft, one bearing being formed with an internal spiral cam of less than one convolution and the same contour as the spiral blade of the cutter head, and the shaft having a follower movably along the cam during the reciprocation of the shaft, said means including a pin fixedly carried by said shaft in predetermined relation with said follower and cooperable with notches formed in the end of the cutter head, the base being also formed with means for supporting an electric motor having a rotary armature shaft and a grinding wheel at the outer end of the armature shaft to coact with the spiral blade of the cutter head during reciprocation and rocking of the shaft mounted in the bearings so as to sharpen the blade.

ELMER P. SACREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 407,721 Cox July 23, 1889 1,147,214 Cross July 20, 1915 1,205,876 End et al Nov. 21, 1916 1,275,218 Calkins Aug. 13, 1918 1,472,827 Erdman Nov. 6, 1923 1,620,847 Whisler Mar. 15, 1927 1,669,919 Trbojevich May 15, 1928 1,686,268 DeVlieg Oct. 2, 1928 2,154,054 Schurr Apr. 11, 1939 2,221,458 Sacrey Nov. 12, 1940 2,332,510 Franzen Oct. 26, 1943 

